Treatment of surface water runoff to remove solid debris and pollutant content is a relatively simple matter when water flow is gradual, whether slow flow, steady flow, or occasional moderate flow. Installations in places such as golf courses, especially in temperate regions, apply water sparingly, and are only infrequently subjected to very heavy rainfall.
During their periods of moderate exposure to rainfall, routine maintenance largely attends to the gradual accumulation of solid materials such as cuttings, branches and the like, and the gradual deposition of pollutants such as oils, pesticides and fertilizers. Regular maintenance will attend to most of these.
If these were the only circumstances, the instant invention would rarely be justified, because there would seldom if ever be a sudden load washed into a drainage system. Indeed, many or most golf courses already have installed drainage systems with these parameters in mind. They simply provide surface drains that lead to storm drain systems, creeks, or rivers without concern for overload, because a heavy load occurs so infrequently as to be tolerable.
Now this tolerance for overload has radically changed. Very recent statutes now exist which forbid or stringently limit the discharge of debris and pollutants into drains regardless of their infrequency. Society's tolerance for solids and pollutants in storm drain systems has been utterly and irreversibly changed.
Again, gradual accumulation of debris and pollutants can reasonably be attended to by street sweeping, routine cleaning of drainage basins, proper maintenance of parking lots, and proper disposition of area trimmings, deposits and pollutants. However, the consequences of heavy storm runoffs are quite different, especially in areas where routine maintenance still can harbor an accumulated burden which would normally have been attended to by routine measures, but which in a heavy storm could wash into the drain system all at once. A large amount of storm water carries with it and dumps into the system a burden which otherwise would have been attended to before it could have reached the drainage system.
Here is where the very evident and objectionable results occur. Storm drains become clogged, surrounding areas become flooded, and accumulated pollutants arrive all at once, and what then does pass through is the accumulated burden of what would normally have been stopped before the storm. The system is simply overwhelmed, and the downstream regions receive all of this material.
With increasing public awareness, the acceptance of trash and pollutants downstream in rivers, lakes, bays and beaches has ended. Instead it has now become the task of proprietors of existing installations to find an affordable system to comply with the new societal imperatives.
It is the problem of the proprietor to install in his activities a system which is at once affordable and sufficient.
It is an object of this invention to provide an affordable system which can readily be incorporated into existing drainage systems, or as a part of a new one.
It is another object of this invention to provide systems which can readily be serviced, and which, in a relatively small bulk can provide a barrier to most or all of the burden in a heavy flow of water from a substantial surrounding area.